One of the most chilling themes in \ufffdJihad\ufffd is that Al Qaeda, which fell to pieces after Americans routed the Taliban in Afghanistan, is back in business and bigger than ever as a result of the invasion of Iraq. Michael Scheuer, a former head of the bin Laden tracking unit at the Central Intelligence Agency, puts it this way: \ufffdThe unexpected gift of the invasion of Iraq has really been more than bin Laden ever dreamed was possible.\ufffd